Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
913 FXUS62 KKEY 281902 AFDKEY Area Forecast Discussion National Weather Service Key West FL 302 PM EDT Tue May 28 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 245 PM EDT Tue May 28 2024 Surface analysis places a stationary front extending from the Gulf coast to the Northeast, with a series of high pressure centers in the North Atlantic. This places the Florida Keys in a region of light and variable flow. In the mid and upper levels, an expansive ridge extends from just east of Central Mexico to the western Bahama Island, which is acting to deflect any shortwave activity away from our area. Nearby KAMX Doppler radar is detecting diurnally- driven, popcorn-variety showers and thunderstorms waxing and waning across the South Florida Mainland. Closer to home, skies are mostly sunny across the island chain, with temperatures approaching their daytime peaks near 90F. Combined with dew points in the upper 70s, feels-like temperatures are in the lower 100s at most locations. For the next several days, the aforementioned weak, chaotic surface flow will continue, with any shower or thunderstorm activity likely driven by subtle boundary layer moisture advection events and residual boundaries from afternoon convection over South Florida. The latest mesoscale numerical weather prediction guidance suggests this could first occur tonight, with scattered shower activity in the vicinity of the Lower and Middle Keys developing after midnight. Given the lack of large-scale forcing for ascent and substantial dry air aloft, nudging towards slight measurable rain chances appears prudent for now, but this will be reevaluated with the evening update forecast package. An area of high pressure currently centered over south-central Canada will dive southeastward over the next several days, pushing offshore of the Delmarva Peninsula by Friday night. This will result in freshened easterly breezes over the weekend through early next week. The origins of this airmass will produce a tight moisture gradient setting up in the vicinity of the Florida Keys. In this scenario, and given the suppressed ridging aloft eliminating much in the way of a mid-level cap, bouts of unsettled conditions typically result, with global MOS guidance often under performing on measurable rain chances. Have retained low- end chain rain and thunder chances for now, but this will be reevaluated over upcoming forecast cycles. The 2024 Atlantic tropical cyclone season begins in a few days. There are early indications of a Central American Gyre (CAG) developing this weekend through early next week. This can often create result in surface cyclogenesis in the vicinity of the Yucatan Peninsula. For now, any developing low would likely drift northeastward harmlessly into the North Atlantic, well displaced from the CONUS. && .MARINE... Issued at 245 PM EDT Tue May 28 2024 There are no watches, warnings, or advisories currently in effect for the coastal waters of the Florida Keys. Light to gentle, generally variable breezes are expected through Thursday. High pressure currently over south- central Canada will emerge off the Mid-Atlantic coast by the end of the work week. This will result in fresh northeast to east breezes beginning as early as Friday night, lasting through early next week. Small Craft Advisories may be required for portions or all of the Florida Keys marine zones as early as Friday evening or Saturday morning. && .AVIATION... (18Z TAFS) Issued at 245 PM EDT Tue May 28 2024 VFR conditions will prevail at both EYW and MTH terminals. Near surface winds will be light and variable through the evening into the overnight hours. && .PRELIMINARY POINT TEMPS/POPS... Key West 82 91 81 91 / 20 10 10 10 Marathon 82 91 82 91 / 20 10 20 20 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...BT Aviation/Nowcasts....AP Data Acquisition.....DR Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest